3.) Solve by using the substitution method. Write your answer as an ordered pair. \[ \begin{array}{l} x+3 y=8 \\ y=2 x-9 \end{array} \] answer:

Step 1 ：First, substitute \(y\) from the second equation into the first equation. This gives the equation \(x + 3(2x - 9) = 8\).

Step 2 ：Simplify the equation to get \(7x - 27 = 8\).

Step 3 ：Solve this equation for \(x\) to get \(x = 5\).

Step 4 ：Substitute \(x = 5\) back into the second equation \(y = 2x - 9\).

Step 5 ：Solve for \(y\) to get \(y = 1\).

Step 6 ：The solution to the system of equations is the ordered pair \(\boxed{(5, 1)}\).